Media content providers provide media content stored on a server to users via one or more computer networks. Generally, individual clients (e.g., subscribers or users) receive media content on client devices (i.e., the device used to display the media content to the user) from media content providers through network links to the source server and display the media content via a media player executing on the client device. The displaying of media content is referred to as playback.
The source server stores copies of the media content as a media file. To transmit the media file, the source server transmits the media file on the network according to the encoded bit rate of the media file. In other words, when source server transmits the media file to client devices, the source server consumes the necessary bandwidth on the network based on the encoded bit rate of the media file to transmit the media file to client devices.
The client devices connect with the network at an established maximum throughput rate. The maximum throughput rate refers the maximum bit rate at which the client devices download the media file from the network. The established maximum throughput rate is based on either underlying technology of the link between the client devices and the network or contracted service levels for the clients. Actual throughput is the throughput rate at which the network conveys the data from the content provider, e.g., source server, to the individual client. The actual throughput to the client may only be a fraction of the maximum throughput based on environmental conditions and competing network traffic.
Since the actual throughput may vary based on environmental conditions and competing network traffic, the rate at which a client's media player must consume (i.e., receive and play) media over a network connection, be it a constant rate or an average rate, to achieve uninterrupted playback may exceed the actual throughput rate of the link between the client device and the network. In other words, the bandwidth required to transmit the media file may exceed the actual throughput rate to the client device from the network. In these situations, the media player must pause to wait for more data from the media content provider to arrive before it can continue to playback the media content. This pause, often referred to as buffering or re-buffering, can greatly diminish the enjoyment of media viewing.